The business of building a connected world, also referred to as the Internet of Things, is rapidly growing. Some industry analysts have estimated that the number of connected devices and systems (in an industrial, consumer, government, and business setting) may rise from five billion devices to a trillion devices over the next ten years. A substantial portion of that growth will be devices and systems using wireless communication, such as over cellular networks.
Common challenges in the controls and management of such connected devices include scalability and operability, not only within a particular vendor's own platform, but among the various platforms being offered by different vendors. One particular intersection of these challenges is the communication protocol used in the controls and management of such devices. These protocols define how devices talk among each other, what they say, when they say it, and who they say it to. Another intersection of these challenges is the architecture defining the organization of these devices.
To promote inter/intra-operability, a flexible protocol is desired. A popular communication protocol and architecture is the Hypertext Transfer Protocol-based (HTTP) REpresentational State Transfer (REST) application programming interface (API), also referred to as “HTTP RESTful API.” REST is a style of software architecture for distributed systems that may employ a standardized interface, such as HTTP. An application conforming to the REST constraints may be described as “RESTful”.
In some implementations, HTTP RESTful API may use open standard formats. Two popular open standard formats include JavaScript Object Notation (“JSON”) and Extensive Markup Language (“XML”) data formatting. Both formats employ human-readable text to transmit data objects and, thus, provide a flexible and open scheme for communication. The trade-off for such open standard formats is verbosity.
HTTP is the foundation of data communication for the World Wide Web (commonly referred to as the “Web”), which is a system of interlinked hypertext documents accessible via the Internet. The Internet collectively describes an interconnected network of computers and networks. Although HTTP is not restrictive as a communication protocol, the usage of HTTP has been limited to unidirectional communication due to traffic routing devices and security devices, such as firewalls and Network Address Translation, employed with a computing and network infrastructure often employ security mechanisms.
HTTP polling is a typical technique used to overcome the unidirectional nature of HTTP across such Internet infrastructure. The technique provides firewall transparency and two-way communication, but at a tradeoff of high reply-message latency responsiveness, high bandwidth consumption, and high server utilization.